MUTATION IN THE CYSTIC-FIBROSIS TRANSMEMBRANE REGULATOR GENE IN A MANWITH BILATERAL CONGENITAL APLASIA OF THE VAS-DEFERENS

A 28 year old man and his 27 year old wife were investigated for infer tility of 3 1/2 years' duration. There was azoospermia caused by bilat eral aplasia of the vas deferens, and therefore it was planned to aspi rate spermatozoa from the epididymis for the purpose of in-vitro ferti lisation. As part of the diagnostic workup the man was investigated fo r those mutations of the cystic fibrosis transmembrane regulator (CFTR ) gene which occur with undue frequency in association with aplasia of the vas deferens. Deoxyribonucleic acid (DNA) analysis revealed a typ ical three base deletion (DELTAF 508). In the wife, CFTR gene mutation s were excluded with 80% probability. The likelihood of cystic fibrosi s in this couple's children was accordingly estimated to be about 0.2% - an acceptable risk. Assisted fertilization in patients with bilater al aplasia of the vas deferens should not be undertaken until they hav e been thoroughly investigated and informed of the risks.